Inking pad



Feb. 6, 1940. w, MlTTAG I 2,189,551

INKING PAD Filed Nov. 24, 1937 INVENTOR 40d ma a w Patented Feb. 6, 1940 1 UNITED STATES PATENT OFF-ICE i 2,189,551 I I INKING-PAD 'Winired-G. Mittag, Ridgew'ood, N.1J. Application November-'24, 1937,- Serial-No; 176,149

4 Claims. (Cl. 91-.54.5)

Tins-invention relates to improvements in inking pads, the -=principal object of the-invention-beingto provide an ink-ing apad' "having an 'ink'reservoir for automatically supplying ink to 'the padthereby to maintainithesame in evenly-inked condition throughout the=life of the pad. A further object of the'inventio'n is to provide an inking pad havingmeans'for distributing over a comparatively large area :a supply of ink; de-

livered to-the pad at asingle-point.

Other objects and advantages .of :theinvention will appear asthe description'proceeds. I In the drawing accompanying this specification, i 5 Fig. 1' is aplan' view-'oftheouter or cover-section of the pad frame;

Fig. 2 is a plan 'view ofthe inner or base section of the pad "frame andshovving the ink reservoir in place therein; v Fig; -3 "is atransverse sectional view taken approximately on the line'33 ofFig. 1; j

Fig. 4 is a side view of the :base section shown iirFig. 2';

"Fig. 5 is "a transverse'sectional view, on an en-' larged' scale; -through the completely: assembled pad;

.Fig. 6 'is a reverse planview ofthe base'section;

Fig. 7 is'a'plan"view,-partly brokeriaway, of the described. For thexsake of Tlightness'andfiexi- .bility the. base member #may be, recessed 'at-its .underside to'iorm aplurality .o'f chambers .:3 "disposed around the lowerportion dffthe wall of chamber the "said chambers "3 iibeing separated from each other byxrac'lia-lly extending walls 4 connecting the wall of chamber '2' with the-outer annularwall l5 surrounding the chambers 3, as shown in 6." "ll'ieannular wall 5 is provided at its outer surface with a plurality of radially extending lugs 6 and with L-shaped recesses 1 adjacent said lugs for cooperation with similar formations onan'd in the cover member thereby the wall ID of "the cover member is -provided'- with inwardly projecting-lugs; I3=and with L-shaped recesses contiguous to said lugs. "Ihe respective lugs and recesses of the cover and base members are so disposed that-thebasemember may be readily inserted into the cover member by causing-the lugs ofeach-of said members to; enter the vertical portions of the recesses of theother member and then, by twisting or slightly turning the base member with relation to -the'cover mamber the lugs of each member will pass into-the "Theinvention, as hereinbefore stated, compre "hends a special form of ink reservoir which will automatically maintain a regular supply of ink to-the pad. As herein-shown the reservoir comprises receptacle I5 of suchdiameter that it will fit'within the chamber "2 of the base member. The upper end of the receptacle is closed by "a cap l6, said cap having a depending tube 11 secured in a hole atthe center of =thecap and extending downward to a point slightl-yabove the bottom of the receptacle. Upon the top surface -of the-cap I5 is supported a flexible diaphragm 18, preferably of rubber, having an annular fiat portion anda centralsphericalportion at the center of which is formed a small perforation or pin hole in axial alinement with the tube 1-1.1 The diaphragm is held in place by a'clampingceap member I9 the center of which is cut out so as "to exposethesphericalportion o'f the diaphragm.

The skirt portion of cap m'ember' t9 fits-snugly "around the "corresponding skirt of cap member 1% while the horizontal portion of cap member 49 provision of an ink-spreading or equalizing ele ment for use in connection with the ink pad "for cooperation with the reservoir above described is i) to cause an even distrubution of the ink throughout the pad. In the drawing the pad is shown as comprising a pair of disks 20, 2| of any suitable thin textile fabric of good wearing quality, between which disks are disposed a pair of felt disks 22, 23. The equalizing member above re ferred to consists of a disk 24 of a moisture resisting fabric disposed between the felt disks. I have found by practical tests that a material such as oil silk is particularly well suited for this purpose. However, I do not wish to limit my invention to this specific material, since any thin material having moisture-and wear-resisting qualities will serve the purpose. The disk 24 is provided with a number of perforations 25 distributed over the area of the disk except at its center portion, which will directly overlie the spherical portion of the diaphragm IS. The disks 20, 2!, 22, 23 and 24 are all secured together by an edgebinding strip 26 of channel form in cross-section and having its edges bent inward so as to grip the disks and fasten them together.

Before assembling the device, a supply of ink isplaced in the receptacle i5 and the diaphragm I8 secured in position by the cap member 19. The reservoir thus assembled is inserted in the chamber 2 of the base member, and the ink pad above described placed over the reservoir. The base member is then placed within the cover member l0 and given a slight turning movement as hereinbefore described, thus locking the base and cover members together and at the same time clamping the edge of the ink pad between the flange H of the cover member and the depression or groove 9 in the top surface of the base member. As shown in Fig. 5, the top of the ink reservoir extends somewhat above the top of the chamber 2, so that when the members are locked together as shown in that figure the center portion of the pad will impinge upon the diaphragm I8, thus normally closing the pinhole in the diaphragm.

vent on to the lower fabric and felt disks 2! and 23, which of course will absorb said ink. When the disks have once become wet by this operation, a certain amount of capillary action is set up which, by reason of the small diameter of the tube, causes the ink to be continuously fed to the disks so long as the stamp pad is in operation. However, upon discontinuance of operation there will be a slow leakage of air through the disks, gradually filling the space between the diaphragm and the cap l6, thus restoring the remaining ink to its normallevel in the tube. Were it not for the equalizing disk 24, after a number of strokes of the stamp on the pad, the

ink would pass freely through all of the disks and eventually the center portion of the pad would be saturated while the portions remote from the center would remain comparatively dry. By the provision of the equalizer, however, the ink at the center of the lower disk 23 encounters resistance to its passage by reason of the solid center of the equalizing disk and is deflected thereby toward the perforations 25 in said equalizing disk, through which perforations it passes to the upper disks. It will thus be seen that whereas the ink is delivered to a single central point of the lower disk, it reaches the upper disk at a plurality of widely separated points so that the ink is evenly distributed over the surface of the topmost disk.

It will be evident that the present invention, by automatically supplying ink to the pad, eliminates the messy job of re-inking the pad by hand.

' Moreover the device affords the advantage that renewed without the necessity of replacing the entire device.

Having thus described my invention what I claim is:

i l. A device of the character described, comprising in combination, a base member, an ink receptacle supported in said base, a stamp pad disposed above said receptacle, and means forming an air chamber between said pad and receptacle, said means being operative upon depression and release of the pad to create a vacuum in said chamber thereby to extract ink from the receptacle and discharge it upon the pad.

2. The combination with a stamp pad, of an ink receptacle provided with a cap for closing the receptacle, a tube mounted in said cap and communicating at one end with atmosphere and at the other end with a plane near the bottom of the receptacle, a flexible diaphragm disposed between said pad and said cap, said diaphragm having a vent perforation in communication with said tube and normally closed by the pad whereby on depression and release of the pad a vacuum will be created between the diaphragm and tube thereby to extract ink from the receptacle and deliver it to the pad.

3. A device of the character described comprising in combination, an ink receptacle having a closing cap, a stamp pad disposed above said cap, flexible means between said pad and receptacle for forming an air chamber above the receptacle, said means being operative upon depression and release of the pad to create a partial vacuum in said chamber, and a tube of restricted diameter communicating at one end with said chamber and at its lower end with the ink receptacle near the bottom thereof.

4. The combination with a stamp pad, of an ink receptacle provided with a cap for closing the receptacle. a tubemounted in said cap and communicating at one end with atmosphere and at the other end with a plane near the bottom of the receptacle, a flexible diaphragm disposed between, said pad and said cap. said diaphragm having a spherical portion disposed centrally thereof in overlying relation to said tube and the center portion of said cap thereby forming an air chamber between the diaphragm and tube, saidaspherical portion having a vent perforation in communication with said tube and normally closed by'the p'ad whereby on depression and release of the pad a vacuum will be created between the diaphragm and tube thereby to extract ink from the receptacle and deliver it to the pad.

WINFRED G. MITTAG. 

